Indicator tube of the glow lamp type



4, 1959 R. LANDREY INDICATOR TUBE OF THE GLOW LAMP TYPE 2 Sheets-Sheet 1 Filed Aug. 29, 1955 INVENTOR.

LEO R. LANDREY ATTORNEY g- 1959 L. R. LANDREY 2,898,500

INDICATOR TUBE OF THE GLOW LAMP TYPE Filed Aug. 29, 1955 2 Sheets-Sheet 2 INVENTOR.

LEO R. LANDREY ATTORNEY United States Patent 2,898,500 7 INDICATOR TUBE OF THE GLOW LAMP TYPE Leo R. Landrey, Wayne, Pa., assignor to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Application August 29, 1955, Serial No. 530,945

2 Claims. (Cl. 313-1095) The present invention relates to indicating devices and more particularly to glow lamp gas tubes for visibly showing any one of a plurality of numbers or characters as predeterminedly-selected.

Neon tube glow devices displaying an array. of numerical characters are known to the art as exemplified by the US. Patent 2,142,106 issued to H. P. Boswau. In general, however, these tubes have been subject to manufacturing difficulties, have required large excitation potentials, and yet did not afford reliable operation. The manner of assembling such tubes is both costly and unsatis factory. Accordingly, it is proposed in accordance with the present invention to provide a novel structural arrangement for the elements of a numerical display tube which is adapted for ready manufacture to provide a sturdy reliable tube of superior electrical characteristics.

An object of the invention is to provide a glow gas tube having simple anode and cathode construction for easy assembly and low cost fabrication. Y

Another object is to provide an anode and cathode as sembly, wherein each cathode number, letter or other character has its own anode in the form of a ring arranged to substantially encircle that cathode character.

Another object is to provide a glow lamp gas tube giving improved stability of breakdown voltage.

Another object is to provide a glow lamp gas tube wherein circuit lead-ins from base pins are individually connected to indicating numbers by traversing insulating tubing supported by perforated ring anodes. Another object is to provide a glow lamp gas tube wherein perforated anode rings, are arranged in spaced stack formation with all leads protected by insulating tubing internally of the stack and thereby eliminating gross use of insulating compounds.

Another object is to provide a glow lamp gas tube wherein perforated stacked anode rings are accurately Referring generally to the drawings and particularly to Fig. 5, one form of the present invention is shown as assembled in an evacuated gas filled transparent envelope 11 having a vitreous base 12, through which a plurality of base pins project for respective inclusion in control I and lamp circuits. A vacuum seal 9 is made in the base 12 to permit a visual inspection of the glow through the smooth transparent top 8v of theenvelopc 11. The en-. velope 11 is filled with a suitable gas such as neon at .the required pressure as will be understood. The indicating lamp assembly, housed in the envelope 11, includes a plu-. rality of anodes 13 and a like plurality of cathodes 14, ten in this instance, operatively arranged to display a selected number, or character, by'applying an igniting po-' tential to a selected cathode. In the present instance, the anodes 13 are of annular washer-like form, specifically rings, arranged to substantially encircler'espectively the cathodes 14, as supported in insulated relation. by the rings. Also as seen from Fig. 4, each ring anode,13. is formed with a major central aperture and two oppositely disposed minor apertures 15, and a row of holes 16 about spaced relative to the character cathodes as a unitary small rugged structure.

A further object is to provide a glow lamp gas tube wherein any selected number. illuminated has a sharply defined configuration. p

A still further object is to provide a glow lamp gas tube wherein means operates to prevent disturbing reflections; and

To provide other improvements as will hereinafter appear.

In the accompanying drawings- Fig. 1 represents a side elevation view of a embodying one form of the present invention;

Fig. 2 represents a top plan view of the same tube showing one number which may be lighted;

Fig. 3 represents a bottom plan view of the tube;

Fig. 4 represents a section on line 4-4 of Fig. 5;

Fig. 5 represents a section on line 5 -5 of Fig.4;

Fig. 6 represents an exploded view of the anode assembly; and

glow tube assembly.

tively fine electrically conductive the washer body, these latter serving to support the'cathodes 14 as will presently appear. Each of the minor apertures is located at a difierent position on the circuma ference of the anode between thezouter and inner annular peripheries. The apertures 15 and holes 16 are. arranged in matching relation when disposed in spaced face to face position, to thereby provide longitudinally aligned straight line passages for circuit leads. A

For mounting the ring anodes 13, each aperture 15 has an eyelet 17 of conducting material fixed thereinhaving an' extension serving as an axial'bushing 18 of the selected length to define the space desired between adjacent an-. odes. A conductive post 20 of good conductivity, such as nickel, leads from base pin A through all of the aligned eyelets 17 at one'side ofthe ring anodes, and "a like wire 21 leads from base pin A through allof the aligned eyelets 17 at the other side of the ring anodes. The respeca tive eyelets 17, posts 20 and wires-21 are bonded to gether for electrical contact. Thus, v all of the ring anodes 13 are supported on the same axis in axially spaced, stacked relation within the envelope 11 and provide an axial sight tunnel through which the centrally located cathodes 14 can be viewed from th'e registering envelope portion 8 to thus observe the, selected glowing cathode. As shown in Fig. 6, the cathodes 14 are formed of relawire respectively having the configuration of numbers OFto 9. The ten character cathodes are preferably arranged in the order shown in Fig. 6 with the character Oi nearest the viewing end wall of the tube structure and the character 1 at the opposite or base end of the tube. a I

For mounting the cathodes 14 in,insulated relation but in close proximity to the ring anodes 13 tothereby support a gaseous discharge about the cathode conductor in response to a potential dilference between the anode and cathode, a plurality of lengths of tubing 22 are provided and arranged to fit snugly respectively in selected anode holes 16 as guides for lead-in wires for the re spective cathodes as may also be seen from Fig. l. The electric field produced between a cathode character 14 and the anode ring 13 in response toyan input signal affords improved ionization, and enables more reliable indication and triggering. Because the an ode' encircles the cathodecharacters, several points on 'eachcharacter are dispersed closely with the anode surface to thereby ass sure that ionization occurs promptly over the' entire-character and is not forl'cedto slowly spread from a single point. This tubing 22 is of insulating materiaLgsuch-fas ceramic Axially considered,,.the ceramic tubes 22 vary in length from one another toqcorrespond. to. the axial positions of the several cathodes and each is arranged t9 l Patented A gterminate on approximately the level of its cathode in order that its internal lead-in wire may be directly connected to one end of its cathode. Preferably these cathode lead-in wire joints are protected by a coating 23 stick as a*pa'ste'consistency Alundum-Ludox mixture for ihsulatio'n'. This particular insulation has been found to be stable and is not subjectto'sputteringand release of unwanted'gases. Thus, for example, the lead-in wire 24 from the base pin 1 passes through a long length of ceramic tubing22to emerge in the plane of the cathode for the numeral 9" for jointing with that number cathode. Likewise the lead-in wire 25 from the base pin 2 passes through a shorter ceramic tube 22 to emerge in the plane of the cathode for the numeral 5' for jointing with that cathode. Similarly, all of the other ceramic tubes 22- carry lead-in wires fromthe respective base pins to connect with the corresponding cathode numbers.

The opposite ends ofthe cathodes to which the lead-in wires are jointed are anchored to mechanically secure the cathode in place by short lengths of insulating tubing 26, which are mounted in conveniently located holes 16 of adjacent anodes. The joints of these ends, with the tubing 26, are coated with insulation 27, preferably an Alundum-Ludox mixture, which extends in the plane of the cathode as seen at 23 in'Figs. 2 and 4' to form an invisible end mask assuring that a glow is established only upon the character forming part of the cathode conductor A.

In Fig. 7 of the drawings a modification of the anode and cathode assembly is shown, as mounted in the glass envelope 11 with base seal 12 and projecting. base pins for the respective anode. and cathode leads. In this form the anodes 30 are rings perforated similarly to the rings' of Fig. 4 and are supported in a like manner by conductive posts 31, at each side traversing eyelets 32 bonded thereto and symmetrically spacing the stacked anodes 30. V

Likewise'the leads 33, from the base pins for respective connection to the several cathodes 34, traverse insulating tubes35 inserted through the anode ring perforations 36, corresponding to the holes 16 of the rings 13 shown in the tube of Fig. 5 and which are similarly spaced circumferentially of the respective anode rings. In this form of the invention; however, the anode rings 30, between the bottom anode 37 and the top anode 38, are respectively arranged between pairs of cathodes. 34, .so that each of such rings functions selectively with one or defined number. Also only the apertures for receiving mounting posts 31 are necessary in the top anodering 38 which does not have mounted thereon a cathode character 14.

From the foregoing it will be seen that ring anodes 13 of Figs. 1 through 6 can be mounted in stacked relation upon the conducting wires and 21 to be uniformly spaced by the eyelets 17, so that all of the holes 16 of each anode 13 are aligned with the like holes 16 of the remaining anodes 13. The ceramic tubing for the lead-in wires can be cut to the proper lengths for the spacing of cathodes, and then pushed into place in the holes 16 for a snug fit. The cathode wires can now be threaded through the respective ceramic tubes for jointing with the proper cathode wires. Such joints are protected by suitable insulation 23 and 27 as heretofore explained.

As finally assembled in the evacuated gas filled envelope, each cathode is substantially encircled by its anode and in consequence the difference of potential effective to distribute the ionized gas substantially uni formly throughout the configuration of the character to be illuminated, results in improved stability of break- 7 down voltage.

It will now be apparent that a novel gas tube of the glow type has been devised which is characterized by ease of assembly, absence of complicated wiring, im proved stability, reduction of insulating compounds, all resulting in sharply defined numbers.

Whatis claimed is:

1. An indicating tube of the glow lamp type comprising a gas-filled transparent envelope having a viewing window and a base, a plurality of tube pins in said base,

7 a plurality of annular anodes each having a major central aperture and a series of minor apertures spaced apart the other of its two cathodes according to the character to be illuminated. Where, as here shown, the tube is to indicate ten numbers there are four anode rings 30 operatively associated with eight member cathodes, the

bottom anode disc 37 for a single cathode and the top anode shield 38 alsofora'single cathode. Preferably the cathode, which operates inresponse to a potential difference with the bottom anode 37, is to display the number 1; and the cathode which operates in response to' a potential difierence with the top anode 38 is to display the 0. The cathodes for the numbers 2 to 9 are conveniently located to prevent interference one with another, the preferred arrangement being as indicated,

and with mounting leads oriented in a manner similar to that of Fig. 6. I I I It should be noted that the bottom anode 37 is in the form of a solid disc instead of a ring in order .to provide amore uniform anode-number, spacing alongthe complete length of the straight'line of the numberl. Also this anode 37 is oxidized to give'a dark surface serving as aback-shield to prevent reflections and add to the tunnel-eflect given by the anode ring stacking arrangement.

'- Also it should be: notedthat1the top anode ring 38 has a smaller inside diameter than thediameter' of the other rings and thus shields any glow at the anodecathode junction where the number lead'emerges from the insulating-tube;- This constr uction ensures a sharply along the surface of the anode, said anodes being oriented parallel to each other with corresponding apertures iii alignment with each other, a metallic eyelet secured to each anode with each eyelet being mounted in the same corresponding aperture in each anode so that said eyelets are axially aligned, a conductive support rod secured to one of said tube pins and carrying said plurality of eyelets whereby said anodes are supported in a stack spaced apart parallel to each other and substantially parallel to said viewing window of the tube envelope, a plurality of indicator glow cathodes each having a characteristic configuration and each having a smaller diameter than the major apertures of said anodes, said cathodes being insulated one from another and oriented parallel to each other and to said viewing window of said envelope, each cathode being in close proximity to one of said anodes to thereby respond to a difference of po tential between the cathode and anode to ionize the gas surrounding the cathode, a plurality of hollow tubes of insulating material oriented parallel to the longitudinal axis of the envelope and extending through the minor apertures of said anodes, each of said insulating tubes carrying a metallic conductor with each conductor being 2. The tube defined in claim 1 wherein the last anode at the bottom of the stack of anodes is positioned between a cathode and the base of the tube, said last anode comprising a solid plate having a surface facing said viewing window and adapted to prevent the reflection of light from a glowing cathode.

References Cited in the file of this patent UNITED STATES PATENTS 

